In the "love bank" couples can "preserve their love for ever, leaving photos or love letters, rings or cinema tickets from their first date", the exhibition's spokeswoman Katarina Javorska told the BBC.

"It's really safe, protected with a special seal. Only they can see what's inside," she explained.

Among the other exhibits at the museum is a "love-o-meter", purporting to measure the strength of a couple's love.

Ms Javorska called the love-o-meter's technology "a big secret". Lovers get their own verse from Marina when they use the machine.

"They hold hands or kiss, and with their other hand they hold a special handle - it measures the electricity in their bodies. Then the verse they get shows the strength of their love."

Ms Javorska said "our goal is to create the next Verona". "That is based on fiction - Romeo and Juliet - but our Sladkovic-Marina story is a real one."

Slovak children memorise verses from Marina, and Slovakia has named streets, and even a town, after Sladkovic.